Water-soluble polymeric films are commonly used as packaging materials to simplify dispersing, pouring, dissolving and dosing of a material to be delivered. For example, packets made from water-soluble film are commonly used to package household care compositions, e.g., a pouch containing a laundry or dish detergent. A consumer can directly add the pouch to a mixing vessel, such as a bucket, sink or washing machine. Advantageously, this provides for accurate dosing while eliminating the need for the consumer to measure the composition. The pouch may also reduce mess that would be associated with dispensing a similar composition from a vessel, such as pouring a liquid laundry detergent from a bottle. The pouch also insulates the composition therein from contact with the user's hands. In sum, soluble polymeric film packets containing pre-measured agents provide for convenience of consumer use in a variety of applications.
Some water-soluble polymeric films that are used to make pouches will incompletely dissolve during a wash cycle, leaving film residue on items within the wash. Such problems may particularly arise when the pouch is used under stressed wash conditions, such as when the pouch is used in cold water (e.g., water as low as 5° C. and/or up to 10° C. or 15° C.), in a short wash cycle, and/or in a low-water wash cycle (e.g., wash liquors from about 3 L to about 20 L). Notably, environmental concerns and energy cost are driving consumer desire for utilizing colder wash water and shorter wash cycles.
Additionally, the pouch must have adequate strength, both after soon after making and upon storage, to withstand forces that may be applied during packing, transport, storage, and usage. Adequate strength may be particularly preferred with the pouches encapsulate liquid compositions, such as laundry detergent, to avoid unintentional bursting and/or leakage.
There remains a need for water-soluble films and related articles such as pouches having the desired characteristics of good water solubility (e.g., cold water solubility), suitable pouch strength, chemical resistance, chemical and physical compatibility with laundry actives or other compositions in contact with the film or pouch formed therefrom, and/or desirable mechanical properties, such as deformability upon thermoforming and/or adequate sealing.